Role of Flavanols in Exercise and Aging

Aging Clinical Trial

Official title:

Acute and Long-term Effects of Dietary Flavanols on Local Control of Skeletal Muscle Blood Flow During Exercise in Young and Old Humans

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01557738
• Other study ID #: 2012-02-0114
• Status: Completed
• Phase: N/A
• First received: March 8, 2012
• Last updated: June 24, 2014
• Start date: December 2012
• Est. completion date: April 2014

Study information

• Verified date: May 2014
• Source: University of Texas at Austin
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

It has well known that diets rich in fruits, vegetables and cocoa products are associated with positive health benefits and these positive effects have been shown to be due to compounds they contain called flavanols. Flavanols have been shown to exert their positive effects by indirectly increasing nitric oxide (NO) bioavailability. NO is a potent vasodilator that is believed to play a role in increasing blood flow to active muscle during exercise. This regulatory process is impaired with healthy aging. The underlying premise to this study is that if NO bioavailability can be increased following flavanol ingestion, will there be a restoration of blood flow during exercise in older individuals? Accordingly, the first part of this research project will compare the acute vascular effects of flavanol ingestion between a young and old group. The investigators have hypothesized that both groups will show an improvement in blood flow to active muscle during exercise, though the magnitude of the change will be greater in the older group. The second part of this project will look at the effects of 4 weeks of daily flavanol ingestion in the old group. The investigators hypothesize that subjects will demonstrate an improvement in blood flow to active muscle during exercise after the 4 week intervention and that the magnitude of the change will be greater than the acute effects. Findings from this proposal will provide evidence for the efficacy of flavanols to be used (as a simple and safe lifestyle intervention) to reverse or combat impaired blood flow regulation in older individuals.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: April 2014
• Est. primary completion date: April 2014
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• Males and Females between 18 - 30 years old

• Males and Females between 60 - 80 years old

Exclusion Criteria:

• cardiovascular and/or microvascular disease

• blood clotting disorder

• pregnant lady

• current smoker (or regularly smoked within last year)

• a history of an adverse reaction to cold

• taking medications known to effect the autonomic nervous system

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Aging

Intervention

Dietary Supplement:
• High Flavanol Trial
The experimental trial (high flavanol content) will involve the consumption of a beverage containing about 1000mg of cocoa flavanols.
• Low Flavanol Trial
The placebo trial (low flavanol content) will involve the consumption of a beverage containing 75 mg of cocoa flavanols.
• High Flavanol Trial; long-term
The experimental trial (high flavanol content) will involve the daily consumption of a beverage containing about 1000mg of cocoa flavanols for 4 weeks. Subjects will be provided with 28 packets of the beverage to take home with them.
• Low Flavanol Trial; long-term effects
The placebo trial (low flavanol content) will involve the daily consumption of a beverage containing 75 mg of cocoa flavanols for 4 weeks. Subjects will be provided with 28 packets to take home with them.

Locations

Country	Name	City	State
United States	University of Texas at Austin: Environmental and Autonomic Physiology Laboratory	Austin	Texas

Sponsors (1)

Lead Sponsor	Collaborator
University of Texas at Austin

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in femoral blood flow during exercise following flavanol consumption	Blood flow regulation to active muscles during knee extension exercise can be assessed by using ultrasound to measure blood flow in the femoral artery. This will be done before and after stimulation of the sympathetic nervous system. A baseline value will be obtained and then the measurement will be performed again 2 hours after flavanol ingestion.	During knee extension exercise, change from baseline in blood flow 2 hours post flavanol ingestion	No
Secondary	Change in flow-mediated dilation (FMD) following flavanol consumption	Flow-mediated dilation is commonly used as an index of nitric oxide bioavailability. Nitric oxide is believed to play a role in blood flow regulation during exercise. A baseline value will be obtained and then the measurement will be performed again 2 hours after flavanol ingestion.	Change from baseline in FMD 2 hours post flavanol ingestion	No